Underreamer



Dec. 8l, 1931.

l.. wrl-:LLs

UNDERREAMER Filed May l2, 1928 2 Sheets-Sheet l -f JG'VENTOR.

` W"Z5. BY @mh 9% ATTORNEY DCC. 8, WELLS I UNDERREAMER Filed May l2, 1928 2 Sheets-Sheet 24 /6 /a f77' 4 f. 5. 5o f "5 ZZ as *i* /6 /6 x/ f 22 00]/ a ao J4 L. :I I

' z v n INVENTOR. 5f WE5.

BY I f /a Y ATTORNEY.

Patented Dec. 8,1931

uNn-EDsTM-ES PATENTOFHCE LENNIE WELLS, or LONG Banen; CALIFORNIA UNnEnREAMnn My' invention` relates to rotaryywell drilling tools, andA more particularly to under reamers to whicnmay ybe attached atool of some sort, said under reamers being adapted to be attached toa rotary member, such as a string of drill pipe and berotated therewith. i t l It accordingly isl an object of my invention to provide a novel form ofwell drilling tool havinga set of rotary cutters adaptedto be expanded outwardly from or retracted within a bodyv ,orV casing, means-being provided Vwithin said body or casing .forv expanding said cutters'foutwardly.

vide a novel form of indicating means `for indicating that the cutters are expanded or retracted, means` being also provided forloperating said indicating means.A l

The above and further objects andadvantages of my invention, as will hereinafter more fully appear, I attain 4by the mechanism described in the specification, and illustrated on the drawings,forming a part of' my application. 1

Reference is u drawings, in which similar reference characers denote similar parts.` In the drawings,

i Fig. 1 is a vertical sectionalrviewof my ini o vention, showing the cutters in retracted position, i Y Fig. 2-is a" taken on the line 2-2, Fig. 1, looking'in the direction of the arrows, l y

Fig. 3 is a similar view takenv on theline `3-8, Fig. 1,

Fig. 4 `is -afpart ysectional `and ypart eleva- =Applicatie; 'filedv May 12,

Another objectof my invention istofpro-` had to the accompanying transverse cross-sectionalview, v

192s; serial No. 277,132.'

I provide a body or casing 2, provided with a hollow portion 4 adapted to house a mandrel 6, preferably detachably a associated ,therewith, the casing or body 2 being provided with a preferably taperedextension 8, screw- 'threaded as at 10 so to associate the same Iwith a rotary member, suohasthe string pipe .o'fa' well drilling equipment, the lower portion of said body, if desired, being provided with a socket'or other-member 12, screw- 60 threadedas at 14, to receive a drillingor other tool.

The body-Qsplovided with a cooligimedium passage 16` aligning withv a similar passage 18 inthe mandrel 6, the lower'I or outlet 55 portion of the passage beingyopened, and

closed by a'valve 20, the function of-which ywill presently be described.V

Mounted within the body 2 is a setof carriages, designatedgenerally bythe numeral 7 .22, which carriages are preferably removable from said body, and are.` unconnected to any part ofthe structure of the device.` These carriages have both a radial and axialmovement with respect to the body 2 or .the mandrel 6, their movement being guided by complementary devices, 24 and 26, respectively on saidcarriag'es and onsaid mandrel, which devices are adapted to coact, asV seen in Figs.

1 and 4, so themovement of said carriages 80 will always behadin unison; Y

With each carriage 22 -I associate in anyv `manner preferred, a cutter 28, preferablyv of the rotary type, and vertically positioned on vertical shafts 30, associated in any preferred manner'with the carriages 22.1` .Y If desired, an inclined cutter 32, also .ofthe rotarytype, andmounted upon an inclined shaft 34, may be provided on each ofthe carriages 22, and Vmovable therewith, both `sets of cutters being adaptedfor special use in connection with hard earth formations, said cuttersfunctioning to chip away such formations; and when said tool is used in other formationsother cutters may be used.

For-the purpose of limiting the downward movement of the carriages 22, I provide the mandrel with ai ledge or other` member 36- for Vengagement with` the. ledges 38 ofthe carriages 22. (Fig. 4). A

To move the carriages 22 outwardly, but not inwardly, I provide a suitable spring 40, which spring rests on the top of a valve casing 42 (Figs. 1, 4 and 6), presently to be described, and its top portion engages a suitable washer or other member 44, surrounding the mandrel 6. The spring 40 moves the washer 44 upwardly, whichwasher `is `in continual engagement with the lower portions 46 of each of the carriages 22, and hence moves said carriagesoutwardly and radially with respect to the body 2 or the mandrel 6, said carriages being guided in theirrmove-v ment by the complementary devices 24 and 26 respectively on thecarriages 22 and the mandrel 6.

The inward movement ofthe carriages 22 (precisely as their outward movement) is accomplished "by .thc engagement of the top portions 48, preferably rounded as seen in Figs. 1 and 4 for this purpose, with the pipe as it is withdrawn from the hole,I the insertion with saidhole being accomplished .b v holding said carriage inwardly against the pressure of the spring` 40 by means of :1 'binding wire, `which is cut or removed after the tool has been inserted in the hole.

The `valve casing 42 has a .top portion '50, preferably screwed on 'to the 'lower portion .of the mandrel 6and as hereinbefore stated, the spring 40 rests thereon, said 'valve casing being held inpos'it'ien bya suitable screw plug 52, cut-away as at 54 to provide a ledge which has a preferably squared portion 5G .cut therefromv (Fig. 7) 4for the vengagement with a suitable tool or wrenchto screw said plug in placeto support the valvecasing42.

rEhat the operator'may continually be '1n- 4formed as'tot'heexact position ofthe cutters V28, (out or in) an .indicating meansor valve 20, pivoted 4as at 60 to the top of said valve casing, and provided with an operating pawl or other member 62. is provided. said valve, when open, as in Fig. 4,.:indicating that the cutters 28are in outward position,the` ,pump

being'in operation when said valve is open,

the circulating medium within 'the passages 116 .and vv18 freely flowing therethrough. lWhen said 'valve is closed, as AindicatedV in vFig. '1, thepassages 16 and 18 are closed, Astopping'the pump.

i It will be .understood .that the valve A20 is opened by Athe press re of the circulating medium; to close .said valve, the bolts "58, preferably screwed tothe 'washer 44 are provided, which bolts are adapted to pass through perforations in the top 50 of the valvecasing 42, one of saidbolts functioning asa guiding means 'to prevent binding, and the other to operate thepawlA G2 to close the 4,valve 20, said bolts, of course, travelling with the washer 44, with or against .the pressure of the spring 40, Yto expand the cutters outwardly, said cutters being retracted Aas fhereinbefore explained. i

"S `tending to hold the valve 20 .adapted 4to tbe In Fig. 8 I have shown a. slightly modified form of indicating means in which the body 2 is provided with the plug 52 and wrench opening 56, the valve casing 42 restingT thereon, and the valve 20', opening and closing the passage 18 of the mandrel 6, bolts 58 being provided as in the other form ot my invention. AIn thiscase, however,.-a pawl 62 is operated by the right bolt 58, a spring in closed position. Theoperation is identical with that previously described,

`llhile I have thus described my invention with great particularity, it will be clear that -the -samelmaybe modified throughout a Wide range. I accordingly do not Ipropose rto be vlimited to .the exact details of construction shown and described, but reserve the right in practice 'to ,make any and all modifications thereof ,that fall withinthe scope ofthe ap-` pended claims.

I claim as my invention: Y

1. In ,an underreamer, a body, a mandrel inserted 'in said body through an opening in the "lower 'portion thereof, means in the lower portion of said'body for vdetachably securing said mandrel `in said body, means in saidopening'for securing said last'mentioned means in position so saidmandrel will remain stationary insaid body, a set.. Vof cutters 4in said body and adapted to be moved relatively to said mandrel, and said body, and means associated with said rmandrel 'for operating said cutters.

2. In an underreamer, insertable in said body through an opening 'in lthe "lower Vportion `thereof, an upper 'member surrounding said mandrel, a lower mem- -ber adapted to be detach ably associated with said mandrel, means associated with said mandrel and posltioned between said members for 'holding said upper member in adjustable relation with said mandrel, means associated with bothof said members wheresaid members are adapted to `move relatively to each other, a detachable support in the lower `portion of said body, for supporting said lower `member', and a set of cutters Aasociated with said :body `and `said mandrel, said cutters being adapted to "be moved by said upper member.

3. In an underreamer, a body, a `hollow mandrel in said body, a set-of movable cutters adapted to be guided by said mandrel, means for projecting said'cutters outwardly from said body, and a double acting lvalve for opening and closing the hollow portion of said mandrel, said valve, when closed, being adapted to cause the Huid pressure thus built up in said hollow 4portion to function as a positive signal to indicate that saideut- .ters are not operating.

4. In an underreamer, a body, a mandrel `in said body having a fluid passage therethrough, a valve cage associated with fthe a body, a mandrelV fil? Y lower portion of said mandrel, a set of cutters in said body, means associated with said valve cage for projecting said cutters outwardly, and a valve in said cage for closing said passage, said valve beingv adapted to indicate tothe operator the operative condition of said cutters.

5. In an underreamer, a body, a mandrel in said body, said mandrel having a circulating medium passagetherethrough, means positioned in the lower portion of said body for holding said mandrel in said body, a 'set ,of cutters in said body and adapted `to be projected outwardly therefrom, means assooiated with said rst mentioned means for projecting said cutters outwardly, a valve for a controlling the lower-'end of said passage, and means associated vwith said first mentioned means for operating said valve.

6. In an underreamer, a body, amandrel in said body, said mandrel having apassage' therethrough, a set of cutters ins'aid body,

d means associated with said mandrel for pro- Vjecting said cutters outwardly from said body, and for permitting said cutters to Y be moved inwardly with said body, a valve for controlling `said passage,'and means associated' with said irstmentloned means for operating said lvalve.` Y f 7. In an underreamer,`abody, a mandrel i in said body,said mandrel having a passage therethrough, a set of cutters,associated with said mandrel and saidbody,means associated with said mandrel for'projecting said cutters outwardly, and permitting said cutters to Y be moved inwardly in said body, a valve for controlling said passage and means associated with said lfirst Vmentioned means for operating said valve and also for holding said valve in closed position. f

In testimony whereof I have signed name to this specification.

LENNIE WELLS. 

